Complex petrophysical correction in the adaptation of geological hydrodynamic models (on the example of Visean pool of Gondyrev oil field)

The authors review a method of combined porosity and volume density correction in the process of modeling the distribution of reservoir permeability. Basing on petrophysical investigations of core samples from Bashkir fold deposits, an association between rock porosity, density and permeability has been analyzed. Significant correlation has been observed for the above mentioned parameters in porous collectors in contrast to reduced correlation for dense rocks and intervals of anomalously high poroperm characteristics. For terrigene porous collectors the authors propose a model of permeability assessment based on combined porosity and density correction. A modified model was developed for Visean pool of Gondyrev oil field, where collector permeability had been calculated as a function of rock porosity and density. The modified model has been compared to the conventional one; significant differences have been detected. In the modified version maximum permeability is associated with the southern part of the pool, whereas the conventional method points out the central part and predicts lowering permeability closer to the periphery. Geological model in the modified version is more homogenous than the conventional one and has no sharp peaks and valleys. The calculations have been made that reproduce the history of field development for both permeability volumes. Authors demonstrate that total oil production obtained using the modified model has a much better correlation with the actual data. The best results from using suggested method apply to the initial stage of development due to better convergence of high-rate wells. On the whole, comparison of two methods shows that for the purposes of production history adaptation the modified model is significantly better than the conventional one. Hence, the method of density correction allows for better justification of differences in the lithology of Visean collectors, which ultimately results in higher accuracy of data on residual oil reserves in the deposit

Selection of Appropriate Quantum-Chemical Model for Calculations of Properties of Chromium Group Complexes via DFT

The selection of a pair of functional/basis for the most adequate quantum-chemical determination of the geometric and electronic properties of chromium group metal complexes with polydent heterocyclic ligands has been carried out. When selecting a suitable model, such parameters as allowable accuracy and acceptable time of calculation have been taken into account. It has been found that the accuracy of calculations depends on the number of basis functions in-volved in the calculation model – the error tends to decrease with the increase in their number. The ac-curacy of calculations also increases with introduction of the polarized orbitals 2d2p and 3df3pd in the quantum-chemical model and the diffuse orbitals p, pp, ppp in the basis, respectively. The results obtained by using non-hybrid functionals with large basis functions are comparable to the calculations performed in less time with the help of hybrid functionals. The optimal ratio for the accuracy of calculation results compared to the time for study of the coordi-nation compounds can be achieved by using the PBE0 hybrid functional and TZVPP basis functions

Highly efficient phosphine-catalyzed routes to α-imidoacrylates and 2,3-diimidopropanoates

[Figure not available: see fulltext.] The highly efficient α- and vicinal bis-addition of cyclic imides to methyl propiolate in high yields and β-addition of these imides to α-imidoacrylates in quantitative yields is reported. These reactions offer a simple metal-free method for a gram-scale preparation of practically useful α-imidoacrylates and vicinal bisimides under mild conditions with high atom economy and selectivity

EAS primary particle parameter estimation with the complex Pamir-XXI detector array

Some new developments in EAS methods made in the framework of the Pamir-XXI project are presented. First, primary energy and direction definition accuracies by a network of fast scintillators are considered, optimum network cell size is defined for 10 PeV showers. Second, the same accuracies for a network of fast optical (Cherenkov) detectors are considered for 30 TeV–10 PeV showers. Third, the possibilities of separation of EAS initiated by protons, nitrogen and iron nuclei of 1 and 10 PeV energies using a wide-angle Cherenkov telescope are discussed. Finally, the results of the extraction of 30–50 TeV gamma showers from the proton shower background with the same telescope are presented. Presumably, our developments can help in the study of PCR mass composition and ultra high energy gamma ray astronomy in other projects

EAS primary particle parameter estimation with the complex Pamir-XXI detector array

Some new developments in EAS methods made in the framework of the Pamir-XXI project are presented. First, primary energy and direction definition accuracies by a network of fast scintillators are considered, optimum network cell size is defined for 10 PeV showers. Second, the same accuracies for a network of fast optical (Cherenkov) detectors are considered for 30 TeV–10 PeV showers. Third, the possibilities of separation of EAS initiated by protons, nitrogen and iron nuclei of 1 and 10 PeV energies using a wide-angle Cherenkov telescope are discussed. Finally, the results of the extraction of 30–50 TeV gamma showers from the proton shower background with the same telescope are presented. Presumably, our developments can help in the study of PCR mass composition and ultra high energy gamma ray astronomy in other projects

EAS primary particle parameter estimation with the complex Pamir-XXI detector array

Some new developments in EAS methods made in the framework of the Pamir-XXI project are presented. First, primary energy and direction definition accuracies by a network of fast scintillators are considered, optimum network cell size is defined for 10 PeV showers. Second, the same accuracies for a network of fast optical (Cherenkov) detectors are considered for 30 TeV–10 PeV showers. Third, the possibilities of separation of EAS initiated by protons, nitrogen and iron nuclei of 1 and 10 PeV energies using a wide-angle Cherenkov telescope are discussed. Finally, the results of the extraction of 30–50 TeV gamma showers from the proton shower background with the same telescope are presented. Presumably, our developments can help in the study of PCR mass composition and ultra high energy gamma ray astronomy in other projects